Method 1:

1.) Under HKLM\SOFTWARE\Microsoft\.NETFramework\policy\ check to see if the
version you want is installed (for example, look for the v1.1 folder and
4322 for the version number to detect the released version of V1.1)

2.) Under HKLM\Software\Microsoft\.NETFramework\InstallRoot get the path
where the Framework is installed. Create a directory string by concatenating
the install root and the version under policy. E.g.
"C:\WINDOWS\Microsoft.NET\Framework\" + "v1.1" + "." + "4322"

3.) Look at the directory, if mscorlib.dll (or another critical .dll to the
.NET framework is there) the runtime is installed.

Method 2:

There's a caveat to this method in that the shim gets left behind when we
uninstall if there is more than one version of the CLR on the machine, but
it still can be useful depending on what version you're looking for:

LoadLibrary("mscoree.dll"); - if this fails then there's no runtime
installed

GetProcAddress("CorBindToRuntime"); - if this fails there's no runtime
installed

CorBindToRuntime("GetRequestedRuntimeInfo");

GetRequestedRuntimeInfo(xxxx); where xxxx is the build number.

This posting is provided "AS IS" with no warranties, and confers no rights.

-L